usb: gadget: f_acm: use usb_gstrings_attach()

Use usb_gstrings_attach() to assign strings in f_acm to assign strings
ids.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2 files changed